OK guys well I am taking pics as we go.
So far we have the front door cards off, the new speakers and tweeters in without a hiccough and working off the standard amp so wiring is ok.
We have also fitted the new amp into the boot - lo and behold when I got there because my car has DAB - it already has an amp which has complicated things no end.
Anyway, we have worked round it and have now removed the back seats and side seals.
Soon will come some wire splicing I suspect...